SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd3f450173d77da4c5b78ac04487624b40fbf017067bd3aac0a4036d7b39ec90' 
  AND token = 'VVf/jlLpoxe46FLCTfeSYuiG0zE32viWKwhFviouUXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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