SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4c4e65b96340733da72da2d1bba6e74c6a315f00ddf515da89f2563b70400b8' 
  AND token = 'YFEzov+9aOKFN8YVwseYPJBZWwZq3jFE2+ZTGrP3js4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}