SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7e6eccf616d93da136924ce6f9458b31aa00ccd8eee369984daa4c1e8f8ebc2' 
  AND token = 'rHTRHqGgAUTGHrW8kJ2bVi+7wXGXqbcWFsPg7AKMkwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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