SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71b0a8248e4d17f6639ac6ddd12ae37cb58b10fdfed30833fba6437685b942fd' 
  AND token = 'ThKTZ9+qYV/TB3p7y2H/1tYXwhPmTfhRbaUnFLkqZug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}