Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab9a768fab501b65fb039f810eef41644cd6f77c5bd3221e62bd4a8a0d58ec55' 
  AND token = '+5dDI0Rj2RAVe6s1nd0nDYLtwS+Ov29AdkHZM+OI7eE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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