SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3554bf6350f3170e1424551155e5783c003a4ec0363049798bcf3525983a6b6f' 
  AND token = 'HoKB70NCGvPy80nFAyp67PvG7SEFign7Fq0XKxOoD1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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