SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5825f7f7c46e6305b414cdbb9bb70633beb0fc3bd53d21aae719edeeeccba54' 
  AND token = 'OT+7uMq+N8uyzbWuwanarOXbyRS7sqBb826dcnV0VzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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