SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8514eece7469f6786cc0f65d47fed363dadb3110f819e116f5a0eb8cfc1b9903' 
  AND token = 'ndeRon8Q6+CzQwgE21ky6HXprZM/+aJtScXSy0nlwwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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