SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eec0763ac201789ef5f30a0bfe266597a70af13a077762958e7ce4a2d797467' 
  AND token = 'ZbdhHasUGXtlRoUzHNR/YKl5QkjIImqDAscgb1Pbap4=' 
  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"
    }
  }
}