SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8a42d22da28d0496daeb6cfea1c6aa660b19314caa21466c4d5ced0ea0105ae' 
  AND token = 'jJJ45mNjjovWMu+SN92prqWMBe5qGwjDVTYwpPywPAc=' 
  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"
    }
  }
}