SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bead270f9ecdf4681eee53e051fdd94423683c6ffef45356672c5903db060a8' 
  AND token = 'j2CetzR94ffqJfZ9rQfinZAk88yj0HfjhkuRf11edCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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