SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4e2aebd27d373fada7d5f488200e7f3c96bcd2fccd6d1f1ef053b36512aecfe' 
  AND token = 'azcS8UgjgIwin4E0O83ziLclKYB/Pn0piD35tKYW62I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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