SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cae918f44c15880650b3e50a64f2e89d0e0582a631833a4024a0798511e72b2f' 
  AND token = 'XHj/Gup/JwVblC+RzQkI/bS6if6YXmWocBIbAfQZkCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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