SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a1e9f3fef51466c65c4edb1390871e60f05b6770fc15484d8caa2760714946b' 
  AND token = 'r5y/8H4yPZqhCoaheUR0xS/Q6Q/aiwGTuyBattjhgw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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