SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59294edb4b28e10bfd72a2c37728ec6fd07bc8afada149a22ef78619800705c6' 
  AND token = 'SG8Nn8b0aoZ5kEkLUKwTwg0Bh96svQKXGw8QrdIeB6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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