SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5d3a62b64e6df13864d6c7650fafbbecec2617f0bc62c6961087a2a70473ba17' 
  AND token = 'mn3JNaL/JpHiNoUQGxQVe5Ngps7u1lMgLKxvneuTOr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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