SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dd6cf5bed576d5a4b22ce8f2e1b5abbf788d7137ff5611ce8ff9b1f2540d7d6' 
  AND token = 'lZgql2uSprU2j9VWUKXb/VtHiwC4g5RofUtJ3jBhhxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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