SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86776659951e8e6f062bdea640d8c3dccdcc863b207b21fcacc6a996ac652bd7' 
  AND token = 'Z+GeHR5b5yXKux8Kx4qLLrG8Xo046rdQkoIlGYs+4M0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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