SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4c021c5614bc3dd5ec73f1ecfb009e520ef92a58163108dab73108293db6dde' 
  AND token = 'XpBUdJItFChwDP+/2FDKvbEvgBq/Pepi1+rMsOXCW+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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