SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deac581cbdee825b69b4c711984c5903e87d7995c18885e712f43c457abc430c' 
  AND token = 'KHIbG2AEIUJ1RnbWJa9SYXrr2bMEz//zAJ8EQD4Mzzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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