SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd6bdfe08a89c69df050fe57a88d249bbed2b0b55ef86ad5efce1a2ab0186cbd8' 
  AND token = 'VABlfjjwlRAY5gWzRnSDNSbyn8LEy+yy6Edz8DIeAmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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