SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de3a05c529bbcafbfddaf2e6e7280d524b58fcfa45714f823a88fe64976904d0' 
  AND token = 'BrCJvuPur8BWeFmlWi4UUQQSCy4SdHKFx0NQlfT6w6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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