SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1af0cba35d414bc54d091ad7cd44a6cd7271b50f12ea329258e1a0c8f0dc9658' 
  AND token = 'SVxKpijByif2SkEM3EjQrNKk7gkI7EYqItVGr058a/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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