SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9635aa817f33dfac7e596654cdd504646d3c2ff4b6bbe68aa18b2912b0996b7' 
  AND token = 'ExPDIIVFN83B7OiQzjNpWJobwGYh4FaqszycYI0gpic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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