SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fee93d21be8a2df52b6034aeacab27705617d6a2c23dc288ad6549f9fc04a00b' 
  AND token = 'SySdxovU/WhfRf5E8hl1xUHE41zFYRnsW55Poto7I94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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