SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40d328e370bf1818861ab132cf5ec28b4546beaaadb367a9f16bbe2e0a13a34d' 
  AND token = 'FOCpcYSSUjODFBLhcxnR3aB/RNKvEVi6u8JIPJtFFp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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