SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c7e00f393248e175ad8a9847f15d905039c7781896a1e14eb8f3f0ca547727e' 
  AND token = 'UmnIzgVJuDP3H/XN3T/kZIR5d8IFh37IDYAwp9NPQog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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