SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '098a1073d195b116d936a8d95e0bd271bdb2526a2854b30e7954f21fb713f746' 
  AND token = '9Q8bB3BRGYF2gFcz/+7Pf9RcvLHPpRxPCOMSTNo7vl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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