SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9eb31ecaf71b77cd8d94e7b62a5223d745db564b165c7c74372dce8c255b41b' 
  AND token = 'KpRkxj6DFXGop3caBgc+u+MyTJ9l1xlIKUnHJhWTqgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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