SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b6f452e548fae791445d1b0c40a8b3e0b24d689ace42cd9c2178190ac62551a' 
  AND token = 'fdSnqrHPvYLaIsdCHPXutak5NlN6IQiQ9fb+4+4vK2w=' 
  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"
    }
  }
}