SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afaba2ef9d622e408b33c2ace5cc5ee99b08079675571f4b22fffda34a514bf2' 
  AND token = 'mRPUascrU9sJyzgGW8iQ9Z3+iDiRm2/hxwlbMj1BrqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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