SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d0889c086a52ccefbb08aaf252372447e603879c17047597ae31e5778317bf1' 
  AND token = 'wDT8Nfts1XdmbHVrQlQNQz0ZMnbwSUwOGk6wnCQn7Lk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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