SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41d035d1b8856a37d10d45cbed682baab407c0aa577a684b409fd25e0024f0f1' 
  AND token = '2wVz0Fy/wvaxXfQ6bGSvr2LnSqeXIDdi76FSAZGjW0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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