SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e37988ac1ccbd7b77699936a7bc8465085847a9fab8666c695885c9276e42cde' 
  AND token = 'h8RyYHByFdBPs8XYZIS+EARLwyUpRuBkDdOgPDnqvPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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