SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9d2f2fa80a42dcadd2693bebbda765937ef2f7a303e0d2f15936995f9ac7f40' 
  AND token = 'PgfhRdC3VSYrAV5aizAdyhkHeGKUEbEQRprhjaVhvNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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