SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '262158af1d5f9f2141fae8cd6ec09e07ac094aff78269325b7c0b98be261c67f' 
  AND token = '2JRFW77NQAJkkaqk8UOfYTxWjzHOqCzKAEQDCfNlA6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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