SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82c1a7836c05a38ab8aadfbdb72ef29c10ae2efb8d7da269bd70b6ea7846cfbf' 
  AND token = 'GQVofhFW3cjQRLbdfKYIOH6/OPflD4s73XXqcOPMSuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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