SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ad922714dd1e91e8076bf28ef915d33a522b42570befa30c816dcc168914c88' 
  AND token = 'jRe3gXduRbDsrb3G7VLugTjUN2q0YdQKn9CxSANkYro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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