SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae7825135b522e37fe10b674aa2d0c0ffdbe83d31ae285ac6ddf8c59332477cf' 
  AND token = 'JN7A3fWLBL331IhguFZ7A+3B5qbzZ32P0Y4TQrdG3Uw=' 
  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"
    }
  }
}