SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6f56a14d4d0df89e0e1f67c7cbb53279f52ab16f6fdf53713af7b2ed133a4d9f' 
  AND token = '8FQEZPVwAUq04KLsHLBGQGvQ5NK3HvmAOxAXSCFmQy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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