SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1be8509782308c6d30529c4d53cd1521e192279b0aed6fc7988c70e2bde08e34' 
  AND token = 'i0zuLHZvuFHMKLdpwTe7CBoQHMF6EFhOw52ISbL0/kM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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