SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cc4bf22a4ba0948f76893f39657b0a53ca8ba22c4cff7c85d02daec58803e89' 
  AND token = 'mlPwFTsRrGfP8NSZJABn39FosFdOAh/6LxydPgBIa7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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