SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '541a3ee3ea769fa8a31c8b8f56e1ab46e4795bc09c4a1041c6ddb048037d8745' 
  AND token = 'gjlMSfussCNHCzrstX61piCuxjV0s9FDZhq+h/nqL3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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