SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a5ff64337083f89cb6e56713b4fb6c2ae869f005cbe510af4ccb700df4781a44' 
  AND token = 'aff9a9VNkwEF5fckcmmSKuh2hI7TnzzK6pKqcHczzEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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