SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6eeb3c16002c7d8ce6268d01e86af439f3c579f6ea881097100e92dc2a3b85bc' 
  AND token = 'E7vlbEwmVObowszRRYwCxAmHUHQedthB7GbpP4BL+W0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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