SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98e5c51c07f9d80c8029bdff4d075924491430de91736e3b3a408c72682247d9' 
  AND token = 'RRYtTNFGxnlnfw0WBmqnza0yYc7TTJ+fdAFHw7/yWhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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