SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4384b04bc1f67ac56b1e704fc99d3514a07ed91adb92d3605562e627c686a590' 
  AND token = 'GNFbEVIjG2LPL2Fft8xKOmjYrorzvDfihateBNffNnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}