SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0797408fac0ca20c3292808278c2ba7a10a772672b7a16b03e43d08b9827fd68' 
  AND token = 'f8rsen3KtazguhfxjzHLOM1uE/dAaUgcbqgtarBvl5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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