SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e04282441305c38c515b23956af9c383328aed3ed32b7b19ffef72a286adb506' 
  AND token = 'L/tpFRZ2PsF8Z0BiTvJf6cB+fBSDV3xcPJjhsobfFX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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