SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab58632e2f49e25d31dc8b143644584230a844ab9d139c5a0aeddd5355e40b4d' 
  AND token = '5H3Oekr7B4qY0igh30p8WErAA1zm3qAkKT6OytXMB5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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