SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '46ddbe7bc4b9309b70bb8390b0d735cea049da7619802999c18413ba67dfa1e4' 
  AND token = '8tfZ4gKYrsKRA8OOIdzUKRk1ibNYqcyndSdqd7VF1VE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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