SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e379be08227f57bfe01cbee228a93b0bf77b22d7c249e385d97fbafe6346784f' 
  AND token = 'Oln1666tUa0qi5JIw5va1latXuEt6PJvfwhc+fe5uTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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