SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74108b42855e734d58a77096d92850af84f3cd78251846af884bfbd6e86044e0' 
  AND token = 'Q0aAWHIbYriOOHw0b7AiBi65w0fzmwhrufz4MfScF2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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