SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fbacdc9d5726d989abfe19362558a34d9ea259d0709ee86d66471e2ce6aebc9' 
  AND token = 'pb7jD0QYTJP8P8HuFEoE/499sBNkiMM34yxptQlCroU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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