SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '066426ad36cbe81e2af3a762ec45764ba41959d4cf4e3dc0994419794e516ff5' 
  AND token = 'pJz47WHg0nVMHaKNnl6kTJZ5tSrs8lZX5u3DWagitfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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