SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '234f9f92fc09bcf55f0cc0b6874c53ad41cb80e341c84cbd9e553e4a8d1bab2f' 
  AND token = '1hEqCOQIs7NfrH2VpPxhcUE7S5fDi/m6yY9wetgnAnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}