SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f129fbc15e491e4d283de3a3553b093586b1b26fb983599040bdb7772d7a829' 
  AND token = 'ZjLLCUSpBmd2wXxDknIlr60OJg18AHlqG7rZVrErIpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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