SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8f88738f08c9192b5d8634d7de37260261aaed651d043de6f69d47916e70035' 
  AND token = 'Z60PeGHDKVCTlA/fICl7bYQETsM/QD47hykp1lFoDjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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