SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ed03c5531c246c54778cdaca91faeb5a5c16309cb62891216726dfa7da9f12a' 
  AND token = 'xKaAeKyh4hRwVBMEYmCMdigmG299ko4yEND1cjPPL6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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