SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dec29af491290a998324a8b68378372a90027ffff3a9ba4eacddefe572272bd' 
  AND token = 'ZpU62AsS1xNnFhFyMppARM+ojPIDYdq+R4R78kcbxMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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