SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c2b3a18fa9b5814dde5b3b835a99da7338c4520966d3b0918714b573fea0da2' 
  AND token = 'jwIyDfvvqccqg/EbnH8vV94y38PkeBioYUdVQBpC3Qc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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