SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7804875a3afebc7835cbd3613fd566f4bbf386268752e0b08a48e99dc847a519' 
  AND token = 'vzLd8TP/2Kx5w9n3+iOZ6yJLUj0MW5mlczPWJVXiyLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00120

JSON explain

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