SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a26256a70e93a89f66200a37e5e528158db4b7cc0ec62755aececd1767b50868' 
  AND token = 'dTDUQhx1byWpAF+m2B4lPzrn6wesze0s60oYvoGUpK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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