SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f9224a555e6019919d05f084143a33cdab43bd2ed56565677dc39a35d2c9156' 
  AND token = '250Lbig0Ii+m5E5OmFyInkntl+nJWu7D6se0wvD6/kA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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