SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90ae0691e0b9084581b29f8093dc038be39386d3e87eea7eb99653a5ed5827c1' 
  AND token = 'BR9GjCMe1t2cb+gPb3dtmo70DRjX6k6w8a7sU0X5mbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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