SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ef34d1d529c10baca287c29b142bd1e0f86ccd15226d396b0ebfe8bdda8e46e' 
  AND token = 'jk6X1Erjis4ogJ8yjV4qrKtYEK+nPHHX60UvNa+tBrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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