SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd03c7fe01ce430de8456ecaab2f750dc737ff29f49bb4f923ff5a4e548cb703e' 
  AND token = 'o+Y9a6JZBslOujFhZcw4M+ogFZgq7vmBRtIZiluELbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}