SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4c582393c292d21fa5da02557f12a96226b9152b87a22bbaaea1fbb5e2da5e5' 
  AND token = 'hL0JEebnWgCuabbTSifo3XyxX+/DU9aF5Bcuz3+yewE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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