SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '365f8438dcceb923b5bbeb5aa8208af2c8dcff170d4e432949c3136b5a05a97c' 
  AND token = 'I6cVcsti/XYhDQ2ktcDxxqXPjHDSWSDoEax6ucPodZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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