SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bafa0ad521a3b3a3d4f05d38fa1093a86d3703716858864892b3464fc17d682c' 
  AND token = 'FIjy/FG+ECOr2ht+/vN0zC3HNbgppJDykIhlmDqaj98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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