SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7f118107aa8850f6c674079ed1f7be76cd68b2aa14fc431ed0af1654093aad8' 
  AND token = 'jJUq74ewbdKTAlxXkOQOmVnyS1f/KctDhwYb9cHeFsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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