SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c5bac67587db74b3dce66a2529ca715ebd5c3910d714cbe71a09655d4648c6da' 
  AND token = 'FpjcoVIBqz+4pMRcMriOZ4mueI/3o0uf5VgxkX1QeLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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